Kamel, S. and Bouabid, R. and Boulangé, B. and Colin, F. (1996) Paléoaltérations hydrothermale et supergène dans un basalte triasique du Moyen Atlas, Maroc. Journal of African Earth Sciences, 23 (2). pp. 225-235.

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Abstract

Triassic basalts in the Mid-Atlas Mountains of Morocco are represented by lava flow sequences. In a vertical transect, consisting of at least four lavas, the basal unit is covered by a paleosol relic. The basalt is tholeiitic with an ophitic texture, and has a mineralogical assemblage characterised by the presence of pumpellyite and chlorite, indicating that the volcanic rocks have been subjected to hydrothermal weathering at high temperatures. The upper part of the basal lavas shows signs of meteoric weathering which is marked by a change in colour (green to reddish brown), presence of Fe oxyhydroxides, transformation of chlorites to smectites, loss of Ca, Na, and Mg, and an accumulation of Fe and Si. This data indicates that the profile was altered before being covered by the overlaying lava flows. The presence of kaolinite and smectite-type minerals suggest that weathering took place under a confined and a moderately-drained environment. The loss of kaolinite in the upper part of the palaeoprofile indicates exposure to thermal metamorphism by overlying basaltic lavas. Copyright © 1996 Elsevier Science Ltd.

Item Type:	Article
Uncontrolled Keywords:	basalt; mineralogy; Triassic; weathering, Morocco, Atlas Mountains
Subjects:	Earth and Planetary Sciences
Divisions:	SCIENTIFIC PRODUCTION > Earth and Planetary Sciences
Depositing User:	Administrateur Eprints Administrateur Eprints
Last Modified:	31 Jan 2020 15:47
URI:	http://eprints.umi.ac.ma/id/eprint/2997

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